I wonder if some people would create a note for each individual house along a block. You’d be able to tell pretty easily that they’re house numbers when looking at them on a map, but not just looking at the text in isolation.
Then again, the better solution would be for osm-website to imitate Discourse and impose a minimum character limit, so that notetakers don’t accidentally waste their time. 
The original post pointed out something I hadn’t considered before: that if the note is about a POI that has closed, it could remain relevant much longer than a note about a POI that has opened. Then again, I’ve encountered notes about closed POIs that have since been deleted from OSM by mappers who weren’t looking at the notes layer.